Clostridium tetani: Clinical manifestations

Nervous REF: Harrison’s Internal Medicine 17^th edition chapter 133

“Tetanus is a neurologic disorder, characterized by increased muscle tone and spasms that is caused by tetanospasmin, a powerful protein toxin elaborated by Clostridium tetani”

When a pathogen infects a species that it does not normally infect, it is often unable to spread effectively from that host, this situation is known as dead end infection or dead end transmission. 

Dead end infections are,

• Leptospirosis
• Legionella
• Endemic typhus
• Tetanus
• Human rabies
• Japanese Encephalitis
• T.solium
• Echinococcus granulosus and Trichinella spiralis

Ans. is ‘b’ i.e., Produces tetanolysin and

Ans. is ‘b’ i.e., Because of tetanospasmin 

• Clostridium tetani is a gram (+)ve, spore forming, anaerobic bacillus.
• Tetanospasmin (neurotoxin) is responsible for tetanus.
• Tetanus is characterized by increased muscle tone (muscle spasm) and rigidity.

Diagnosis of tetanus

• The diagnosis of tetanus is based entirely on clinical findings. The diagnosis is established on the basis of

history of an injury, (particularly one in which either soil or fecal material has been introduced) 6-12 days before the

onset of typical clinical findings.

• Wound should be cultured in suspected cases. However, C. tetani can be isolated from wounds of patients

without tetanus and frequently cannot be recovered from wounds of those with tetanus.

• Other laboratory findings may be –

i)        There may be leukocytosis

ii)      Muscle enzyme levels may be raised

iii)    Electromyogram may show continuous discharge of motor units and shortening or absence of the silent

interval normally seen after an action potential. 

Treatment of tetanus

• Treatment of tetanus includes :‑

1)       Antimicrobial therapy :- Antibiotic therapy is administered to eradicate vegetative cells, i.e. to eliminate the

source of toxins. Penicillin and metronidazole are first line drugs. Clindamycin and erythromycin are alternatives for penicillin – allergic patients. (Tetracycline is not used).

2)       Antitoxin :- is given to neutralize circulating toxin. Human tetanus immune globuline (TIG) is the

preparation of choice.

3)       Control of muscle spasms :- Many agents, alone or in combination, have been used to treat the muscle spasms

of tetanus, which are painful and can threaten ventilation by causing laryngospasm or sustained contraction of ventilatory muscles. Benzodiazepines (Diazepam, larazepam, midazolam) are used most commonly. Alternatives are Barbiturates and chlorpromazine. Mechanical ventilation with a nondepolarizing neuromuscular blocking agent may be used for spasms unresponsive to medications. Other agents include propofol, dantrolene, intrathecal beclofen, succinylcholine and magnesium sulfate.

4)         Respiratory care :- Intubation or tracheostomy, with or without mechanical ventilation may be required.

5)       Autonomic dysfunction :- For sympathetic overactivity labetalol, esmolol or clonidine may be used.

Vaccine :- Patient recovering from tetanus should be actively immunized

Ans. is. ‘d’i.e., Tetanus may be transmitted through dust and droplets

Transmission of tetanus

.   Tetanus is acquired by contamination of wounds with tetanus spores.

.   It is transmitted through contamination of wounds by tetanus spores in the dust.

.   Transmission may occur through a range of injuries from trivial pin pricks to unsterile surgery and compound fractures.

.   It is not transmitted by droplets.

Transmission of Legionella, listeria and leptospirosis has been explained.

Ans. is ‘c i.e., Tetanus 

B i.e. Wounds contaminated with faecal matter

• Wounds containated with fecal matter & soil are most prone for tetanus developmentQ
• Tetanus may develop in chronic conditions, such as skin ulcers, abscesses, and gangrene, burn, frost bite, middle ear infections. It is also associated with surgery, abortion, child birth, body
piercing, and drug abuse notably skin popping”, and open fractures etc

Ans. is ‘b’ i.e., Tetanus 

Source Vs Reservoir

Source

o The source of infection is defined as “the person, animal, object or substance from which an infectious agent passes or is disseminated to the host”.

          In other words, Anything from which a man acquires infection is the source of infection.

Reservoir

o Any person, animal, arthropod, plant, soil or substance in which an infectious agent lives and multiplies & metabolizes.

o Infectious agent is dependent on reservoir for survival.

o It reproduces in reservoir in such manner that it can be transmitted to susceptible host.

A reservoir acts as a source of infection when a person acquire infection directly from reservoir.

So, a resrvoir may sometimes act as a source, i.e., source may be a part of reservoir sometime (not always). Example

o Source & reservoir are same —› Tetanus spores survive in soil (reservoir) and a person acquires infection directly from soil (source). So, soil acts as reservoir as well as source.

o Source & reservoir different —> In typhoid, bacillus survives and multiplies inside human cases or carriers (act as reservoir), but immediate source of infection is feces or urine of patients, or contaminated food, water or milk (act as source).

o So, source may or may not be a part of reservoir. In other words reservoir may or may not act as a source. In simple words : ‑

o Man acquires infection from source.

o Infectious agent metabolizes and replicates in reservoir

Ans. is “`d’ i.e., Tetanus 

Ans. is ‘b’ i.e., More common in winters and dry weather

o Tetanus is common in areas where soil is cultivated, in rural areas, in warm climates, during summer months, and among males.

o Infection is acquired by contamination of wounds with tetanus spores.

o Reservoir of infection :- The natural habitat of organism is soil and dust. The bacilli may be found in the intestine of many herbivorous animals, e.g. cattle, horses, goat and sheep and are excreted in their feces. The bacilli may be found in the intestine of man without causing ill effects.

o Tetanus is one disease in which herd immunity does not protect the individual.

Ans. is ‘b’ i.e., Tetanus 

• The most common initial complaint is pain and stiffness of the jaw, progressing to trismus, risus sardonicus (“sardonic grin”), and opisthotonus over several days.
• Uncontrollable and painful reflex spasms involving all muscle groups are precipitated by minimal stimuli and can result in fractures, rhabdomyolysis, hyperpyrexia, and asphyxia.
• The patient remains awake during the spasms. In survivors, the spasms may persist for days or weeks.

Ans. is ‘a’ i.e., Cl. Tetani 

Ans. is ‘b’ i.e., First symptom to spasm

Ans:B.)Tetanus.

The Image Shows Sardonic Grin.

Clinical Manifestations of Tetanus

• Refusal of feeds, apathy and excessive unexplained cry are the common initial symptoms.
• “Trismus (spasm of masseter muscle) is the most common symptom of tetanus. It is seen in about 50% of patients with tetanus”.
• Headache restlessness and irritability                                                       
• Dysphagia neck muscle spasm.
• Risus Sardonicus due to spasms of facial and buccal muscles.       
• Opisthotonos (Arched posture)
• Seizures                                                                                                                 
• Respiratory muscle spasm 

Ans. a. It is transmitted